The type of retirement plan that guarantees a specified level of retirement income is a defined benefit plan.
A defined benefit plan is a type of retirement plan in which the benefits are defined, or determined, in advance, typically by a formula based on the employee's salary and years of service. It is a pension plan that guarantees a specified level of retirement income to the employee. These plans are typically funded by employer contributions, and the employer bears the investment risk. They are becoming increasingly rare, as many employers are moving toward defined contribution plans, such as 401(k)s, which do not guarantee a specific retirement income level for employees.